Apparatus and method for disintegrating fibrous material



H. D. STUCK Nov. '3, 1959 A APPARATUS AND METHOD FOR DISINTEGRATINGFIBROUS MATERIAL Filed Nov. 18, 1955 3 Sheets-Sheet 1nnnnnnunnnnnnnnpnunnn INVENTOR HAROLD D. srucK.

ATTORNEYS.

H. D. STUCK Nov. 3, 1959 APPARATUS AND METHOD FOR DISINTEGRATING FIBROUSMATERIAL Filed Nov. 18, 1955 3 Sheets-Sheet 2 INVENTOR. IVA/FOLD fl.STUCK.

PQM

ATTORNEYS.

Nov. 3, 1959 H. D. STUCK 2,911,334

APPARATUS AND METHOD FOR DISINTEGRATING FIBROUS MATERIAL Filed Nov. 18,1955 3 Sheets-Sheet- 3 HVVEN TOR,

HAROLD ,0. 6706K.

Pia/1AM EM ATTORNEYS.

United States Patent APPARATUS AND METHOD FOR DISINTEGRAT- IN G FIBROUSMATERIAL Harold D. Stuck, Andover, Mass., assiguor to John W. Bolton &Sons, Inc., Lawrence, Mass., a corporation of Massachusetts ApplicationNovember 18, 1955, Serial No. 547,670 14 Claims. (Cl. 162-17) Thisinvention relates to a machine and method for disintegrating fibrousmaterial for use in the manufacture of paper.

The invention relates particularly to the disintegration and separationof fibers by agitation by churning in a tank rather than todisintegration and separation of fibres between the rotors and statorsof such machines as beaters, Jordans and similar refiners.

It has heretofore been proposed to provide a single nonpressurized tankwith a rotating impellor blade therein for agitating fibrous materialfed thereinto. Usually the tank is charged, the charge agitated in thetank for a predetermined time and the charge is then entirely drawn ofi,with the vat remaining empty until the next charge is supplied thereto.In some such devices, instead of a batch operation, a small portion ofthe charge is continuously extracted through a screen below liquid leveland additional charge is continuously fed to the vat to produce acontinuous process.

The principal object of this invention is to provide a machine andmethod which treats continuously supplied fibrous material, successivelyand continuously in batches with the successive batches being dischargedat a regular rate, fully and uniformly treated.

An important object of the invention is to provide a device forloosening the pith portion of the stalk, as well as scrubbing off thewax on the rind surface, of vegetable fibrous material as bagasse,bamboo, ramie, jute and kenaf or straw to separate out long fibres, andbundles of such fibres of uniform cross section, free from damage. Amajor portion of this objective is accomplished bythe pieces hittingagainst each other while thoroughly wet and at high temperature.

Another object of the invention is to provide a machine and method fordisintegrating fibrous material in which all of the material receives apreliminary disintegration 2,911,334 Patented Nov. 3, 1959 ice the nextsucceeding tank until finally passing through all the tanks in theseries.

A continuous flow of softened fibrous material introduced into theapparatus is thus converted into a uniform intermittent discharge fromthe exit end whereby the apparatus operates continuously at a regulatedflow.

It should be noted that movement of the fibrous mixture through themixing tanks of this invention is not the result of a siphon action, noris there any rotary device such as a roll, brush or the like tending todirect the mixture from one tank into the next. In this invention theimpellers create a churning action in each tank causing periodic upwardsurges and the mixture moves from one tank to the next only when itslevel is raised by surging sufiiciently to be ejected or vomited intothe next tank or compartment of a tank.

In the drawings:

I Fig. l is a side elevation in section on line 1-1 of Fig. 2 ofapparatus according to this invention. I Fig. 2 is a plan view, insection on line 22 of Fig. 1.

Fig. 3 is an end View in section on line 33 of Fig. 1 with the bafileplate broken away.

Fig. 4 is an end view in section on line 4-4 of Fig. l. Fig. 5 is anenlarged plan view of a vaned impeller.

Fig. 6 is an enlarged side elevation of the impeller shown in Fig. 5.

Fig. 7 is a diagrammatic illustration of typical fibrous pieces, such asbagasse, as fed to the apparatus of this invention, and a Fig. 8 is adiagrammatic illustration of the long fibres, or fibre bundles, screenedout at the exit end of the apparatus.

and only material already-preliminarily treated is passed is to provideoutlet In the embodiment selected for illustration of the apparatus: andmethod of this invention, a hollow casing 20 is provided whichpreferably is formed by two substantially identical shells 21 and 22.Each shell 21 or 22 includes an outturned conduit 23 or 24 at one endand includes an opening 25 or 26 at the opposite end encircled by anoutwardlyprojecting flange-27 or 28. The. shells 21 and 22 are elongatedand'the longitudinally extending interior walls thereof,- are formedinto at least two, and preferably three concave lobes such as at 30, 31and 32 in shell 21 and 33, 34 and 35 in shell 22.

The shells 21 and 22 are joined, open end to open end, by suitable bolts36 through the flanges 27 and 28, but shell 22 is upside down relativeto shell 21. In addition, a laterally extending partition 37 is providedbetween the shells together with suitable gaskets such as 38. The casing20 is supported generally horizontally whereby the outturned conduit 23is upturned to serve as an inlet-to the casing and the outturned conduit24 is downturned to serve as an outlet to the casing. A laterallyextending ;Still another object of the invention is to provide .a

novel cooperation between .a rotary vaned-impeller and a lobular-sidewalled tank whereby a liquid fibrous mix ture therein is rotated by theimpeller, caused to surge upwardly and downwardly and continuallydirected back inttithepath of the impeller, thereby loosening the fibresfrom thematerial in an unusually efficient manner. A'still furtherobject of the invention to provide a series of tanks in which a fibrousmixtureis subjected to churning agitation and caused to surge and swirlwith porend wall member 40' is provided just in advance of thedownturned outlet conduit 24 and a series of two tanks 41 and 42 arethus formed within casing 20.

Because of the inversion of one shell relative to the other, the concavelobes 30 and 32 of shell'21 meet along the bottom centre thereof and theshell is wider at the bottom than at the top formed by lobe 31. On theother hand in shell 22 the concave lobes 33 and 34 meet along the topcentre of the shell and the shell is wider at the top than at-the bottomformed bylobe 35. The intermediate side of thelongitudinal centre lineof the casing as shown in Fig. 3. The top of the end wall member 40 isspaced.

' from'the top of shell 22 to form an exit tibns'ofth'e' mixture in eachtank erupting or vomiting into passage or aperture 44 into the outletconduit 24. a The first tank ill and its succeeding tank 42 are thusarranged to contain a liquid fibrous mixture up to a predeterminedlevel, that level being determined by the height of the passages 43 and44 above the bottom of the tanks;

The flanges 27 and'28 are not of uniform width throughout theircircumference and when shell 22 is inverted relative to shell 21 it willbe noted that the tank 42 is on a slightly lower level than tank 41.Tank 42 is thus deeper, narrower and of less length longitudinally thantank 41. Preferably the casing 20 is supported by an adjustable thrustscrew 45 with its longitudinal axis on an inclined plane whereby thetank 42 may be raised with relation to tank 41. This causes the end wallmember 4%) to present a higher barrier above the liquid level and belowthe passage 44 for increasing dwell of the liquid mixture in the secondor last tank 42, as well as in the first tank 41.

In tank 41 an impeller 47 is provided, rotatable around the shaft 48 asan axis of rotation, the shaft 48 being driven by a motor 49 mounted ontop of shell 21. A suitable bearing 59 for the lower end 46 of shaft 48is provided in the bottom of shell 21. The impeller 47, as shown in Fig.and Fig. 6 consists of four vanes in the form of a cross, two oppositevanes 51 and 52 being right triangle shaped and flat while the other twoopposite vanes 53 and 54 are upturned and downturned at 55 and 56respectively. The impeller 47 rotates in a plane extending generally inthe direction of the lobes of the tank rather than in a plane generallyat right angles to the lobes as in certain pulping devices of the priorart. Similarly the axis of rotation of the impeller instead of runningparallel to the lobes is more nearly at right angles thereto. It ispreferred that the shaft 48 of the impeller 47 in the first tank 41 beinclined toward the outlet passage 43 in partition 37 to urge themixture in the direction of the passa e while agitating, churning,surging and swirl ing the same. The edges of the vaned impeller 47 arebeveled but blunt rather than sharp, in order to segregate the fibreswithout cutting, shearing, abrading or otherwise changing the nature ofthe fibres.

The upturned and downturned vane tips 55 and 56,

when revolved at high speed, tend to throw the lower central portion ofthe fibrous mixture in tank 41 outwardly to swirl peripherally in thetank and at the same time tend to surge the peripherally revolvingportion of the mixture upwardly and downwardly in the tank. At the sametime, the concave lobes 3t) and 32 tend to guide the peripherally movingmixture back into the centre of the tank into the path of the impeller47, thereby giving the mixture a thorough, preliminary,segregation-treatrnent. At a predetermined time of dwell in tank 41, aportion of the upper outer peripherally moving fibrous mixture surges,erupts or vomits over intermediate partition 37 through the partitionpassage 43 and into tank 42. This continually occurring successiveejection of individual batches of the mixture is compensated by thecontinuous introduction of untreated fibrous material through the inletconduit 23, or by some other desirable means, so that the predeterminedliquid level in the tank remains substantially constant.

Preferably hot water, or other desirable liquid, is continuouslyintroduced through inlet 23'from a'suitable sourceof supply such as pipe58 along with-a continuous supply of softened fibrous material. Theliquid is preferably at about 150 F. and since the tank is notpressurized, no appreciable digestion action occurs. The hot water actsas a vehicle or carrier in assisting in the segregation of the fibrefrom the fibrous material so that effective separation takes place andthe hot water continuously drips out the outlet 24 in the same quantityas it is introduced into the inlet 23, except immediately. after aneruption. The fibrous material and liquid introduced together anduniformly into'inlet 23, is immediately caught.

up in the swirl created by impeller 47 and lobes 31 and and drawninwardly and downwardly in the manner of a churn despite the surging ofthe mixture mentioned above.

In tank 42 an impeller 60 is provided, rotatable around the shaft 61 asan axis of rotation, the shaft 61 being power driven by a motor 62. Asuitable bearing 63 is provided at the bottom of tank 42 for the lowertip of shaft 61. Impeller 6%) is identical with impeller 47 and rotatesin a plane generally in the direction of the lobes 33, 34, of the tank,but the plane of rotation is angled away from outlet passage 44 andtoward the passage 43 in partition 37. Thus the axes of rotation ofimpellers 47 and 60, formed by shafts 48 and 61 are in the centrallongitudinal vertical plane of casing 20, but are inclined toward eachother in that plane with an imaginary meeting point above the casing.While impeller 47 urges mixture toward its outlet passage 43, impeller60 is inclined to urge mixture away from its outlet passage 44 in orderthat the dwell in the second tank will be longer than the dwell in thefirst tank. The ejection operation is the same, however, in the secondtank, even though consuming more time.

The portions of fibrous mixture ejected through passage 43 are receivedinto the surging mixture created by im- ;peller 69 and lobes 33, 34 and35 and are immediately submerged and further treated in the lowercentral portion of the mixture as well as in the lower outer portionthereof. After prolonged swirling and surging in tank 42, upper, outerportions of the mixture eventua ly surge to the point that they areejected over the end wall member through passage 44 and out of outlet 24in the form of successive individual batches of desegregated fibrousmaterial.

Preferably a screen 64 is mounted below outlet 24 to pass the liquid inthe mixture together with the soluble separated material such as pith,wax and the like. The segregated fibres are caught by the screen 64 andmay be removed for further treatment in any convenient manner.

Preferably a laterally extending bafiie' plate 65 is pro vided just inadvance of the outlet passage 43 in partition 37. The bafiie plate 65 isimperforate and extends from the top of tank 41 downwardly to a linebelow the level of the passage 43 and below the predetermined liquidlevel in the tank. Plate 65 functions to prevent back surge or back flowfrom the tank 42 through passage 43 and into tank 41 but does notadversely affect the ejection operation of the tank 4'1. In addition,the plate 65 not only assures that a new supply of fibrous materialcannot pass immediately through passage 43, if by remote chance itescapes the churning action, but also tends to hold'back the mixture intank 41 except for the portions thereof surging upwardly and outwardlyin rear of the plate.

As shown in Fig. 1 and Fig. 2, the partition 37 is not merely a verticalwall but preferably is provided with a convexed forward and rear face 66and 67 arcuately curved both in plan and in elevation to guide themixture most efficiently and to prevent the creation of dead space orpockets. The end wall member 40 also includes a convexed rear face68 butthe forward face 69 is concave, lobular and closely spaced to the pathof the impeller 60 at its lateral centre point. This lobular forwardface 69 increases the tendency of the mixture to be retained in thesecond or final tank 42 until it has been thoroughly and completelydisintegrated.

In operation, the casing 20 is arranged horizontally at the desiredangle of tilt, such as that shown of 57 in Fig. 1, to create apredetermined liquid level in the series 7 of tanks 41 and 42therein'and to control the dwell in each tank. Hot water at about 150 F.is supplied from pipe 58 into inlet conduit 23 until the tanks 41 and 42are up to the predetermined level and the water com mences to drip outthe, outlet 24 in the same amount as is being supplied. The motors 49and 62 are then started causing the blunt edged impellers 47 and 60 toswirl and surge the contents of their respective tanks. A continuoussupply of the fibrous material, for example bagasse in mash form or thelike, is introduced byhand or mechanically into the inlet conduit 23whereupon it is pre tion of the impeller47 and the lobular interiorwalls of the tank; Portionsoi the mixture are periodically ejectedthrough passage 43 into tank 42 and are again surged, swirled andagitated by the churning action created by impeller 60 and the'lobularwalls of the tank. After a longer dwell. for treatment in tank 42,portions of the fibrous mixture are erupted, vomited or ejected out ofpassage 44 into outlet 24. The thoroughly desegregated mixture, ejectedfrom, outlet 24 in successive batches, passes through the, screen 64except the fibres therein which are caught by the screen and the fibresmay be removed therefrom in any desirable manner. (See Fig.8.) I

In the case of,bagasse, the sections of stalk received from sugarcanevfactories in-pieces about two inches long and one halfinch wide arefirst subjected to an enzyme solution for a period such as ten toseventeen minutes, to enable the enzymesto' consume the proteins,pentosans and sugars in' the ba gasse. The mash 75 of enzyme treatedbagassestill includes both desirable fibre and undesirablepith (see Fig.7) but when passed through the method and apparatus of this invention,the pith and fibre are separated and the fibre 76 may be screened out,as explained above, and the enzymes recovered.

, -It has been found that placing the impellers high in the tankscauses'the surging and churning action to be too pronounced and it is,therefore, preferred that the impellers be close to the tank bottom asshown, to secure a longer dwell. I do not. desireto be limited to thestructure of the particular embodiment illustrated herein as it will beapparent that various changes may be made therein within thescope of theinvention. For example, aseries of more than two tanks may be provided,each tank I having substantially "horizontally extending lobular sidewalls, a;vaned.impeller rotating in a substantially horizontal plane,and an outlet above the normal liquid level, and the tanks may becreated in a one piece casing rather than by the use of a plurality ofshells. Similarly the height of the lateral partitions and outlets maybe adjustable to' further control dwell in the tanks and the height-ofthe impellers on their shafts may be adjustable for a similar purpose. I"f The soft'ened, enzyme treated, mash 75, which may be bag'asse,1isdiagrammatically illustrated in Fig. 7. The product; of the method-andapparatus described herein is-diagrammatically illustrated in Fig. 8. Itshould be I noted that the pith, -wax and other undesirable, soluble,

materials have been separated out leaving long single fibres such as 76or long fibre bundles of substantially uniform cross sectionas at 77. a

-"I :laim:"-

1. Apparatus for continuously disintegrating successive batches offibrous material, said apparatus comprising a tank adapted to contain afibrous liquid mixture, said tank having laterally extending end Walls,one of said end walls having an outlet aperture in the upper portionthereof, said tank having longitudinally extending bottom and side wallsinteriorly formed, below the level of said outlet aperture, into atleast two longitudinally extending -ofrotation is inclined, whereby thefibres in the lower portion of the mixture are continuously segregatedand urged upwardly'into the outer, upper portion of said mixture andsaid outer, upper portion periodically surges up to the level of saidoutlet aperture to emit successive batches of segregated fibres throughsaid outlet aperture.

2. Apparatus for continuously disintegrating successive batches offibrous material, said apparatus comprising a series of tanks eachsucceeding the other and successively connected by passages connectingthe upper portions thereof, the first tank in the series having an inletand the last .tank in the series having an outlet; rotary impellerchurning means within each tank operable below the level ofsaidpassages, inlet and outlet and adapted to impart a rotary,fibre-submerging movement, around an upstanding inclined axis ofrotation, to a liquid mix ture therein, and eruption means, includingsubstantially horizontal, concave, lobes in the bottom and side walls ofeach said tank, cooperable with said churning means, to periodicallyeject a portion of the rotating mixture in each tank upwardly into thenext successive tank through the passage therebetween and toperiodically eject a portion of the rotating mixture in the last tankupwardly into said outlet whereby a fibrous mixture continuously fed tosaid first tank is successively submerged, swirled and dis-- integratedin, and batches thereof erupted from, each tank of the series andfinally erupted from said last tank with the fibrous materialdisintegrated.

3. Apparatus for continuously disintegrating successive batches offibrous material, said apparatus comprising a longitudinally extendingcasing divided by at least one lateral partition into at least twolongitudinally extending tanks, each tank I being adapted to contain afibrous liquid mixture and having longitudinally extending bottom andside walls interiorly formed in the lower portion thereof into at leasttwo longitudinally extending, concave, lobes, the'first said tank havingan inlet for receiving a continuous supply of liquid and a continuoussupply of said fibrous material, each partition between said tankshaving a connecting passage in the upper portion thereof, and the lastsaid tank having an outlet in the upper portion of a wall thereof, and arotary impeller in each said tank, below the level of said passages andoutlet, each said impeller being revoluble on an axis of rotationinclined from the vertical in a longitudinal direction and being adaptedin cooperation with said lobes to disintegrate fibres in'the lowerportion of its tank while urging the mixture therein upwardly andoutwardly in thedirection in which its axis of rotation is inclined,whereby the upper outer portion of the mixture in each tank isperiodically ejected upwardly and outwardly through a passage into thenext succeeding tank andfinally out of the outlet of, the last tank insaid casing.

4. A combination as specified in claim 3 wherein said casing includesmeans for adjusting the central longitudinal axis thereof atpredetermined angles to control the. dwell of mixture therein. i

5. A combination asspecified in claim 3 wherein the axis of rotation ofthe impeller in one tank is inclined toward the outlet passage of thattank to decrease dwell and the axis of rotation of the impeller inanothertank is inclined away from the outlet passage thereof to increasedwell of the mixture therein.

6. A combination as specified in claim 3 wherein the impellers in saidtanks are eachtonned with four blunt edged vanes in the form of a cross,at least two opposite vanes being of triangular outline with one saidvane being upturned at its free end and the other said vane beingdownturned at its free end.

7. A combination as specified in claim 3 wherein each tank includesthree longitudinally extending concave lobes in its interior walls, saidlobes being uniformly spaced from the longitudinal axis of the rmpectivetanks, but the three lobes of one tank being at a different angularposition around said axis from the lobes of another tank whereby onetank is wide at the bottom and narrow at the top and another tank iswide at the top and narrow at the bottom.

8. A combination as specified in claim 3 plus a baflle plate extendinglaterally across at least one said tank at a spaced distance in advanceof the outlet of said tank, said plate depending downwardly from the topof the tank to below the level of said outlet and adapted to prevent 7back flow and back surge from the next succeeding tank through saidoutlet.

9. Apparatus for treating fibrous material, said apparatus comprising apair of substantially identical, elongated, hollow casings, each havingone end formed with an outturned conduit at one end and an opening atthe opposite end and each having longitudinally extending interior wallsin the form of three concave lobes uniformly spaced from thelongitudinal axis thereof, said casings having outturned flanges aroundsaid open end and being connected to each other by said flanges with onecasing inverted relative to the other whereby one outturned conduitforms an upt u'ned inlet at one end of the tank formed by said casingsand the other outturned conduit form a downturned outlet at the otherend of said tank, a

. laterally extending partition, having a connecting passage in theupper portion thereof at the flanged joint of said casings dividing saidtank into first and second compartments; a laterally extending end wallmember, within the second compartment just in advance of the downturnedoutlet thereof, the top of said member being spaced from the top of saidcompartment to form an outlet passage therefor; a motor driven vanedimpeller in the first compartment revoluble on an axis of rotationobliqued from the vertical in the direction of the outlet passage ofsaid compartment and a motor driven vaned impeller in the secondcompartment revoluble on an axis of rotation obliqued from the verticalin a direction away from the outlet passage of said compartment, theimpeller and lobes of the first compartment cooperably segregatingfibres therein and ejecting a portion thereof periodically through saidoutlet passage into the second compartment and the impeller and lobes ofthe second compartment cooperably segregating fibres therein, with alonger dwell then in the first compartment, and ejecting a'portionthereof periodically over said end wall member and out said downturnedoutlet.

10. A combination as specified in claim 9 wherein the flanges of saidcasings are adapted to connect said casings at slightly different levelswith the level of the second compartment below the level of the firstcompartment.

11. A combination as specified in claim 9 wherein the tank formed bysaid casings includes means for supportingthe same with its longitudinalaxis inclined slightly from the horizontal, upwardly from the inlet endto the outlet end. v

12. A combination as specified in claim 9 wherein the plane of the topof the end wall member of the second compartment is higher than thebottom of the passage through said intermediate partition and a bafileplate is mounted across said first compartmentin advance ofthe passagethrough said intermediate partition adapted to prevent back flow. v

13. Apparatus for continuously disintegrating successive batches offibrous material, said apparatus comprising an elongated tank having aninlet and an outlet 0ppositely disposed in the upper portion of the endwalls thereof; horizontally extending lobe means in the side walls andbottom of said tank and power driven rotary impeller means in said tank,proximate the bottom thereof, said impeller being revoluble on anupstanding axis of rotation inclined toward one of said end walls, saidlobe means and said impeller means being below the level of said inletand outlet for co-operatively submerging fibrous material receivedthrough said inlet and disintegrating the same in said tank whileperiodically erupting successive batches thereof upwardly into saidoutlet.

14. A continuous method of treating and disintegrating fibrous materialwhich comprises the steps of continuously feeding fibrous material,accompanied by liquid at a temperature of about E, into a first rotarymixing and churning operation for preliminary segregation of fibresthe-rein; then drawing said fibrous material inwardly and downwardlyinto said mixing and churning operation to completely submerge the same;then periodically erupting successive batches of fibrous material andsaid liquid upwardly out of said first rotary mixing and churningoperation and into succeeding similar rotary submerging, mixing andchurning operations for complete segregation of fibres therein andfinally, periodically erupting successive batches of fibrous materialand said liquid upwardly out of the last said rotary, submerging, mixingand churning operation into a screening operation for separation of saidfibrous material from said liquid.

References Cited in the file of this patent UNITED STATES PATENTS

1. APPARATUS FOR CONTINUOUSLY DISINTEGRATING SUCCESSIVE BATCHES OFFIBROUS MATERIAL, SAID APPARATUS COMPRISING A TANK ADAPTED TO CONTAIN AFIBROUS LIQUID MIXTURE, SAID TANKL HAVING LATERALLY EXTENDING END WALLS,ONE OF SAID END WALLS HAVING AN OUTLET APERTURE IN THE UPPER PORTIONTHEREOF, SAID TANK HAVING LONGITUDINALLY EXTENDING BOTTOM OF SIDE WALLSINTERIORLY FORMED, BELOW THE LEVEL OF SAID OUTLET APERTURE, INTO ATLEAST TWO LONGITUDINALLY EXTENDING CONCAVE LOBES AND SAID TANK HAVINGTANK INLET MEANS FOR RECEIVING A CONTINUOUS SUPPLY OF LIQUID AND ACONTINUOUS SUPPLY OF SAID FIBROUS MATERIAL AND A ROTARY IMPELLER IN SAIDTANK BELOW SAID OUTLET APERTURE, SAID IMPELLER BEING REVOLUBLE ON ANAXIS OF ROTATION INCLINES FROM THE VERTICAL